Manufacture of high octane gasoline



Jan, 26, 1954 R. A. FINDLAY MANUFACTURE OF' HIGH OCTANE GASOLINE FiledSept. 25, 195o INVENTOR. R.A. FINDLAY #Mm M mz .620 Al SE f A TTORNEVSPatented Jan. 26, :1954

UNITED STATES ATENT OF F ICE;

MANUFACTURE OF HIGH OCTANE GASOLINE Delaware Application September 25,1950, Serial No. 156,523

3 Claims. l

This invention relates to a process for the manufacture of high octanegasoline, by treatment of ordinary gasolinas such as straight rungasolines, natural gasolines. Such gasolines are known to boilsubstantially throughout the ap. proximate range of 90 F.-400 F., whichis Ithe usual gasoline boiling range. In one of itsV aspects the.invention relates to the solvent extraction of a gasoline with a solventand under conditions such as to obtain from said gasoline certain highlydesired components thereof which may then be used as such or blendedwith other materials to form a final gasoline product having high octanerating or value. I n another of its aspects the invention relates to asolvent extraction process for; the treatment of a gasoline wherein asingle solvent is employed in a manner such asy to allow its use in bothstages of a two. stage solvent extraction of a gasoline to. separate thesaid gasoline into fractions which can bel as follows:

l. A highly aromatic fraction containing light naphthenes,

2. A highly paraiiinic fraction containing '7 carbon atoms and higherparains,

3. A hexane concentrate which will contain neohexane which can berecovered therefrom as a very highly desirable component and 4. A highlynaphthenic concentrate or fraction boiling above about 220 F.

According to this invention it has been found possible to manufacture ahigh octane gasoline by solvent extraction with a suitable solvent, forexample, furfural, provided said solvent is ernployed in at least a twostage operation or process. Thus, it has been found that it is possibleto first treat a gasoline with for example furfural by solventextraction to obtain an extract phase containing the lighter naphthenesand most of the aromatics originally present in said gasoline and arainate phase containing heavy naphthenes and paraiins and to thenseparate from said raiiinate by solvent extraction with for examplefurfural the said heavier naphthenes and light paraflins following whichthe highly desirable light paraflins can be separated from the heavynaphthenes by conventional distillation or fractionation.

Preferably the gasoline treated according to the invention isdepentanized before the solvent extraction steps are practiced.

Therefore, in its preferred form the process of this invention comprisesthe steps in combination and in the order as follows:

(a) Depentanizing a gasoline; (b) subjecting said depentanized gasolineto (Cl. ISG-14.26)

of the aromatios originally presentin saidv gasoline and a raihnatephase containing heavier naphthenes and paralins originally present insaid gasoline;

(c) Recovering separately from saidextract. phase the lighter naphthenesand aromatics, on the one hand, and solvent, on the other,

(d) subjecting said raiinate to solvent extraction with said recoveredsolvent and under oonditions suitable to form a second extract phasecontaining heavier naphthenes and light parafins and a second raffinatephase; and'V Y (e) Recovering separately from said second; ex-

tract phase a light paraffin concentrate, heavier naphthenes andsolvent.

In order to more fully illustrate the concept and process of thisinvention reference is made to the drawing in which a gasoline suppliedthrough line l to a fractionator 2 is depentanized in said fractionator,the pentanes and any lighter materials being removed from fractionator 2through line 3, and the depentanized gasoline is passed through line iinto solvent extractor 5. Solvent is introduced intov the. top ofextractor 5 through line 6 wherein a rst raffinate containing heaviernaphthenes and parans is formed and taken off through line 1 whilesolvent containing light naphthenes (boiling 12C-220 F.) and most of thearomatics is withdrawn as the extract phase from the bottom of saidextractor through line 8. The rst rafnate is passed through line 'i toextractor 9. The extract phase withdrawn from extractor 5 through line 8passes to fractionator Ill in which aromatics and light naphthenes areremoved as overhead through lines H and i2. Some of this overhead isused as a reflux for extractor 5 and is passed thereto through line i3.Hot solvent from the bottom of fractionator it is removed through lineI4 and passed to extractor 9 wherein it is employed to produce a secondraflinate, which is passed to a solvent recovery system, through line I5and a second extract phase which is passed through line It to afractionator il wherein a hexane concentrate, a heavy naphthenesconcentrate (boiling 22o-320 F.) and solvent are removed through linesIt, I9 and 20, respectively. Heavier naphthenes are used as reflux forextractor il and to this end are passed thereto through llne 2l.Obviously, the extractors 5 and 9 are lled with liquid moving incounter-current directions and the so called reiuxing thereof iseffected at the bottoms thereof.

'I'he temperatures in extractors 5 and 9 are usually in the ranges80-110 F. and 15G-200 F., respectively, preferably in the ranges 90-100F. and 1GO-180 F., respectively. It is possible, by employing a greaterratio of solvent to hydrocarbon in the second extractor than is employedin the first extractor, to operate both extractors at substantially thesame temperature.

It is now obvious that the invention provides 'a' unitary and highlyeconomical as Well as very practical process for the preparation of avery desirable gasoline component and indeed by suitably operating thesystem it is possible -to extract the lightest hexanes, for exampleneohexane into the rst extract if desired, although this is not nowpreferred. The final Asolvent recovery step can be an extraction bypentane followed by fractionation if needed or desired. Thus, in theevent that the extracted hydrocarbons boil close to furfural, or formazeotropes with it, a pentane extraction, as described, can bepracticed.

Equivalent solvents as well as equivalent steps falling within the scopeof the claims appended hereto obviously will be within the scope of oneskilled in the art in possession of this disclosure.

The drawing which is a flow plan of but one form of apparatusarrangement suitable for effecting the process of this invention isschematic only. Accessories such as pumps, temperature indicators, etc.have been omitted for sake of simplicity. Supply of omitted parts of theapparatus as well as process conditions required to place the inventioninto use will be Within the skill of the art in possession of thisdisclosure.

I claim:

1. In the manufacture of a high octane gasoline from a gasoline selectedfrom the group consisting of straight-run and natural gasoline the stepswhich comprise in combination, and in the order as follows, (a.)depentanizing one of said gasolines boiling substantially throughout theapproximate range of 90400 F. (gasoline boiling range), said gasolinecontaining substantial proportions of light and heavy naphthenes, lightand heavy parains, aromatics and including hexanes; (b) subjecting saiddepentanized gasoline to a solvent extraction with a solvent and underconditions causing formation of an extract phase containing said lightnaphthenes and substantially all of said aromatics, and a raffinatephase containing said heavy naphthenes and said light and heavy parains;'(c) recovering separately from said extract phase an aromatics andlight naphthenes fraction on the one hand and solvent on the other; (d)subjecting said rainate (obtained in step (b) hereof) to solventextraction with said recovered solvent and under conditions causingformation of a second extract phase vcontaining heavy naphthenes andlight paraiins and a second ranate phase; and (e) recovering separatelyfrom said second extract phase a light paraffin concentrate containinghexanes, a heavy naphthenes concentrate and solvent.

2. A manufacture according to claim 1 wherein the solvent is furfural,the rst solvent extraction is effected at a temperature in the range-110 F., the extract phase contains light naphthenes boiling in therange -220 F. and substantially all of any aromatics originally presentin said gasoline and wherein the second extraction is effected at atemperature of 200 F. and the extract phase contains heavy naphthenesboiling in the range 220-320 F.

3. The process of claim 1 wherein the hexanes are separately recoveredand blended with a gasoline whose octane value is to be improved.

ROBERT A. FINDLAY.

References Cited in the file of this patent.

UNITED STATES PATENTS Number Name Date 2,026,729 Bray et al. Jan. 7,1936 2,055,455 Taylor et al Sept. 22, 1936 2,087,455 Stratford July 20,1937 2,106,234 Bray Jan. 25, 1938 2,115,144 Keith Apr. 26, 19382,143,472 Boultbee Jan. 10, 1939 2,146,039 Whiteley Feb. 7, 19392,346,639 Andrews et al Apr. 18, 1944 2,369,497 Stanly Feb. 13, 1945

1. IN THE MANUFACTURE OF A HIGH OCTANE GASOLINE FROM A GASOLINE SELECTED FROM THE GROUP CONSISTING A STRAIGHT-RUN AND NATURAL GASOLINE THE STEPS WHICH COMPRISE IN COMBINATION, AND IN THE ORDER AS FOLLOWS, (A) DEPENTANIZING ONE OF SAID GASOLINES BOILING SUBSTANTIALLY THROUGHOUT THE APPROXIMATE RANGE OF 90*-400* F. (GASOLINE BOILING RANGE), SAID GASOLINE CONTAINING SUBSTANTIAL PROPORTIONS OF LIGHT AND HEAVY NAPTHTHENES, LIGHT AND HEAVY PARAFFINS, AROMATICS AND INCLUDING HEXANES; (B) SUBJECTING SAID DEPENTANIZED GASOLINE TO A SOLVENT EXTRACTION WITH A SOLVENT AND UNDER CONDITIONS CAUSING FORMATION OF AN EXTRACT PHASE CONTAINING SAID LIGHT NAPHTHENES AND SUBSTANTIALLY ALL OF SAID AROMATICS, AND A RAFFINATE PHASE CONTAINING SAID HEAVY NAPHTHENES AND SAID LIGHT AND HEAVY PARAFFINS; (C) RECOVERING SEPARATELY FROM SAID EXTRACT PHASE AN AROMATICS AND LIGHT NAPHTHENES FRACTION ON THE ONE HAND AND SOLVENT ON THE OTHER; (D) SUBJECTING SAID RAFFINATE (OBTAINED IN STEP (B) HEREOF) TO SOLVENT EXTRACTION WITH SAID RECOVERED SOLVENT AND UNDER CONDITIONS CAUSING FORMATION OF A SECOND EXTRACT PHASE CONTAINING HEAVY NAPHTHENES AND LIGHT PARAFFINS AND A SECOND RAFFINATE PHASE; AND (E) RECOVERING SEPARATELY FROM SAID SECOND EXTRACT PHASE A LIGHT PARAFFIN CONCENTRATE CONTAINING HEXANES, A HEAVY NAPHTHENSE CONCENTRATE AND SOLVENT. 